Cal. HSC § 25299.96

The priority for payment of a joint claim submitted under this article shall be based on the date on which the board receives a complete application. For purposes of this section, an application shall not be considered complete until the applicable local agency or other regulatory agency confirms the existence of a commingled plume and the joint claimant submits an agreement which complies with paragraph (7) of subdivision (a) of Section 25299.93.